1. Field of the Invention
The present invention relates in general to a lancing device used to puncture the skin and collect a small quantity of blood, and in particular to a disposable lancing device intended to be discarded after a single use.
2. Description of the Related Art
Self-collection of small quantities of blood is sometimes necessary for medical purposes. For example, for patients with diabetes, it is necessary for the patient himself to regularly collect his own blood in order to periodically check blood sugar level (Self-Monitoring of Blood Glucose: SMBG). Lancing devices have been in use for some time to enable such self-collection of blood to be carried out safely and dependably.
Such lancing devices typically have a structure in which a spring member and a lancet having a skin puncture needle are housed within a housing. By extending the tip of the skin puncture needle out from the housing through urging of the lancet by the spring member, the skin puncture needle punctures the skin surface so that a small quantity of blood is exuded. Particularly in recent years, with a view to preventing spread of the HIV or hepatitis B virus through the agency of used skin puncture needles, lancing devices of disposable type designed to be discarded after a single use have come into widespread use.
With lancing devices of this kind, the skin puncture needle is covered beforehand by a resin protective cap in order to maintain the skin puncture needle in a sterile condition until use. Specific examples of lancing devices furnished with such a protective cap are disclosed inter alia in US Patent Application Publication NO. US-A-2007/135828, International Publication No. WO2005/110227, and International Publication WO2006/060128. Such a protective cap must first be detached from the lancing device, e.g. by twisting and breaking it off prior to use, and considerable inconvenience is associated with the need to detach the cap and dispose of the detached cap.